CVE-2026-21097 in Samsung
Summary
by MITRE • 09/09/2026
Improper authentication in ActivityTaskManagerService prior to SMR Sep-2026 Release 1 allows local privileged attackers to launch arbitrary activity.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified within the ActivityTaskManagerService component represents a critical failure in access control mechanisms, specifically categorized under CWE-287: Improper Authentication. This flaw exists prior to the scheduled SMR September 2026 Release 1 update and affects systems where this service manages the lifecycle of application activities. The core technical deficiency lies in the insufficient verification of user privileges before executing activity-related commands. In a properly secured system, any request to launch or manipulate an activity must be rigorously authenticated against the requesting process's declared permissions. However, due to this implementation error, the service fails to validate whether the caller possesses the necessary elevated rights, thereby allowing processes with lower privilege levels to execute actions reserved for higher-privileged entities.
From a technical perspective, ActivityTaskManagerService is responsible for managing the stack of activities and their transitions within an operating system or application framework. When this component does not enforce strict authentication checks, it creates a pathway for local privileged attackers to bypass security boundaries. An attacker with access to a lower-privilege account can craft specific intents or service calls that target the ActivityTaskManagerService. Because the service accepts these requests without verifying the sender's identity or permission level, the system proceeds to launch arbitrary activities as if they were initiated by an authorized administrator or system-level process. This effectively grants the attacker control over application flow and state management capabilities that should be restricted.
The operational impact of this vulnerability is significant, particularly in environments where multiple applications run with varying levels of trust. By launching arbitrary activities, a local attacker can potentially escalate privileges to gain access to sensitive data protected by higher-level permissions. This could lead to unauthorized disclosure of confidential information, modification of system settings, or the execution of malicious code under the guise of legitimate application processes. Furthermore, this flaw aligns with ATT&CK technique T1055: Process Injection and related privilege escalation methods such as T1068 Exploitation for Privilege Escalation, as it allows an attacker to manipulate system behavior by hijacking standard service functions. The ability to launch arbitrary activities can also facilitate further attacks, including phishing simulations within the application interface or bypassing security controls that rely on activity state integrity.
Mitigation strategies must focus on implementing robust authentication checks at the entry points of the ActivityTaskManagerService. Developers should ensure that every method call is preceded by a verification step that confirms the caller holds the required android.permission labels or equivalent system-level privileges. Implementing strict input validation and enforcing least-privilege principles will reduce the attack surface. Additionally, applying the vendor's upcoming SMR September 2026 Release 1 patch is essential as it addresses this specific authentication gap. Until the update is applied, administrators should restrict local access to affected systems and monitor for unusual activity patterns that may indicate exploitation attempts, such as unexpected background process launches or unauthorized state changes in managed applications.